Prototype status
The interface is still under review, but the data engine is now live. We validated the gravity target maths against the standard ABV formula (ABV = (OG − FG) × 131.25), confirmed the honey planning uses a 79.6% fermentable sugar assumption (≈305.7 gravity points per kilogram per litre), and double-checked the Fermaid AT, yeast, and Go-Ferm doses against the club’s metric playbook.
A 20 L, 12% ABV benchmark batch now matches our hand calculations within rounding tolerances: the builder recommends an OG of 1.101, 6.64 kg honey, and 26.5 g/L residual sugar when finishing at 1.010. Keep noting any typing friction or accessibility quirks so we can polish the experience while we extend the feature set.
Batch outputs
Enter batch details to estimate gravity targets, honey needs (assuming honey is 79.6% fermentable sugar), and Fermaid AT additions at 0.35 g per litre.
- Target original gravity (SG)
- Pending calculation
- Estimated residual sugar (g/L)
- Pending calculation
- Honey needed (kg)
- Pending calculation
- Yeast addition (g)
- Pending calculation
- Go-Ferm (g)
- Pending calculation
- Rehydration water (mL)
- Pending calculation
- Fermaid AT (g)
- Pending calculation
Metric brew day checklist
General instructions
- Clean and sanitise everything that will come into contact with your must.
- Dissolve honey in a small volume of water (leave headspace so you can top up to the batch volume later).
- Add water so the fermenter holds your target batch volume minus the amount reserved for yeast rehydration.
- Aerate the must with a drill stirrer or shake/stir vigorously for 15 minutes.
- Rehydrate, temper, and pitch yeast per the Go-Ferm instructions below.
- Record specific gravity and temperature for future reference.
- Apply an airlock. Ferment within your yeast’s recommended range; around 16 °C suits most wine strains.
- Degas twice per day for the first week of fermentation.
- Dose nutrients per the Fermaid protocol below.
- Rack when gravity is stable for two weeks. Also rack within three weeks of a sediment layer forming to avoid off flavours.
- When the mead clears, bottle and enjoy. Most batches are ready to drink after 2–3 months.
Go-Ferm rehydration procedure
For two packets of yeast, dissolve 12.5 g Go-Ferm Protect in 250 mL hot water (the hotter the better).
- When the water cools to 40 °C, pour in the yeast and give the slurry a quick swirl.
- After 15 minutes, begin tempering the yeast by adding 125 mL must to the slurry every five minutes.
- When the slurry temperature is within 6 °C of the must, pitch the yeast into the fermenter.
Fermaid AT nutrient protocol
The total additions for this schedule are 22.3 g Fermaid AT, split into four staggered nutrient additions. Degas the must and dissolve each nutrient dose in about 250 mL of must before adding it to the fermenter. Fermaid AT is a balanced complex nutrient containing both organic and inorganic nitrogen, so no separate DAP is required.
- 24 and 48 hours after pitching yeast: add 5.6 g Fermaid AT each time.
- 72 hours after pitching: add 5.6 g Fermaid AT.
- At the one-third sugar break (for example, when a 1.120 starting gravity reaches 1.080), or no later than seven days after pitching: add 5.5 g Fermaid AT.
- If the mead shows signs of yeast stress (e.g. sulfur aromas) after the final scheduled addition, supplement with an extra 2–3 g Fermaid AT as needed.
This prototype does not estimate pH; plan to measure it with a calibrated meter or narrow-range strips.